What Is Terminal Velocity?
- 1 What is terminal velocity in simple words?
- 2 What speed is terminal velocity?
- 3 Do heavier objects fall faster?
- 4 Can you survive terminal velocity?
- 5 How fast do humans fall per second?
- 6 What is the highest terminal velocity on Earth?
- 7 What would fall faster a feather or a brick?
- 8 Can you survive a 10 Metre fall?
- 9 What is the highest fall a human has survived?
- 10 How do you explain terminal velocity to a child?
- 11 Why is it called terminal velocity?
What is terminal velocity in simple words?
What is Terminal Velocity? Terminal velocity is defined as the highest velocity attained by an object falling through a fluid. It is observed when the sum of drag force and buoyancy is equal to the downward gravity force acting on the object.
What speed is terminal velocity?
Speed Skydiving is the fastest non-motorized sport on Earth. The goal is to achieve, in freefall at the standard jump altitude, the fastest average speed possible over a scoring time of 3 seconds, which can be achieved anywhere between 4000m (aircraft exit altitude) and 1700m above ground.
The last 1000m of freefall distance is required to slow down before deploying the parachute. Freefall speed is measured by a GPS device mounted on the skydiver’s helmet. The speed achieved by a human body in freefall is slowed down by air resistance and body orientation. In a stable, belly-to-earth position, terminal velocity of the human body is about 200 km/h (about 120mph).
A stable, freefly, head-down position produces a speed of around 240-290 km/h (around 150-180 mph). Further minimizing body drag and streamlining the body position allows the skydiver to reach higher speeds of 530 km/h (330 mph). In thin air at higher altitudes, reduced air pressure allows an increased freefall speed of far more than 1000 km/h with the well-know Stratos jump of Felix Baumgartner who holds the top speed record of 1,357 km/h (843 mph).
What is the maximum speed a falling object can reach?
How Fast Is Terminal Velocity? How Far Do You Fall? – Because terminal velocity depends on drag and an object’s cross-section, there is no one speed for terminal velocity. In general, a person falling through the air on Earth reaches terminal velocity after about 12 seconds, which covers about 450 meters or 1500 feet.
- A skydiver in the belly-to-earth position reaches a terminal velocity of about 195 km/hr (54 m/s or 121 mph).
- If the skydiver pulls in his arms and legs, his cross-section is decreased, increasing terminal velocity to about 320 km/hr (90 m/s or just under 200 mph).
- This is about the same as the terminal velocity achieved by a peregrine falcon diving for prey or for a bullet falling down after having been dropped or fired upward.
The world record terminal velocity was set by Felix Baumgartner, who jumped from 39,000 meters and reached a terminal velocity of 1,341 km/hr (834 mph).
Can you go faster than terminal velocity?
Terminal velocity is the speed at which your aerodynamic drag equals your weight. So of course you can increase or decrease your terminal velocity by changing your shape or attitude. So if you’re falling in a streamlined form, you are falling faster than your terminal velocity in a spread-eagle form.
Do heavier objects fall faster?
Gravity In a vacuum, an object on the surface of the earth accelerates downwards at g = 9.81 m / s 2 due to gravity. This is known as free fall. The force of gravity is given by
If gravity is the only force acting ( F = F g ), the object experiences a constant acceleration. Assuming the object has been dropped from rest, its speed and distance traveled can be determined through integration:
Notice that the object’s motion is not affected by its mass, weight, density, or any other measurement of its size. In fact, all objects fall at the same rate in a vacuum as long as the only force acting on them is gravity. Air resistance An object that falls in real life is subject to air resistance.
Note that for a spherical object made from a given material with a given shape moving at a given speed, the drag force is proportional to its area, while the inertial mass is proportional to the volume. By Newton’s Second Law, the acceleration the object experiences due to the drag force is inversely proportional to its radius.
At lower speeds with smooth flow, the viscosity of the fluid is more important and tends to create more drag than at higher speeds. The nature of the fluid and speed of the flow are captured by another dimensionless number, the Reynolds number R :
For a given shape of object, the drag coefficient can be written as a function of the Reynolds number. In particular for spheres, for small values of R, R < 10, the flow is approximately smooth (laminar); C d is roughly 24 R, For values of R between 10 3 and 10 5, the flow is turbulent, and C d is roughly constant at 0.47. For values of R between 10 and 10 3 , C d is between 24 R and 0.47. For the purpose of this demonstration assume the following function for C d R : C d = 24 R , R < 24,47,47 , R ≥ 24,47 Stokes' Law Stokes' Law, applicable for laminar flow, expresses the drag force on a sphere in terms of the speed. Substituting C d = 24 R in the drag equation and using L = 2 r and A = π ⋅ r 2, you get: F d = 6 π μ r v Terminal velocity As the object falls, its speed increases, and so does the amount of drag it experiences. In the limit, at a certain speed called terminal velocity, the net downward force of gravity is balanced exactly by the drag. The terminal velocity can be determined by equating the force of drag to the force of gravity and solving for the speed. If the flow is laminar, the terminal velocity is: v ∞ = m g 6 π μ r If the flow is turbulent, the terminal velocity is: v ∞ = 2 m g ρ f C d A Equations of motion The equations of motion are found by setting F = F g + F d and integrating: Laminar flow:
Can you survive terminal velocity?
Humans cannot survive falls through the air at terminal velocity, therefore significant changes in either the anatomical make up of a human, or the density of air would need to be made.
How far do you fall in 2 seconds?
Example – The first equation shows that, after one second, an object will have fallen a distance of 1/2 × 9.8 × 1 2 = 4.9 m. After two seconds it will have fallen 1/2 × 9.8 × 2 2 = 19.6 m; and so on. The next-to-last equation becomes grossly inaccurate at great distances.
If an object fell 10 000 m to Earth, then the results of both equations differ by only 0.08 %; however, if it fell from, which is 42 164 km, then the difference changes to almost 64 %. Based on wind resistance, for example, the terminal velocity of a skydiver in a belly-to-earth (i.e., face down) free-fall position is about 195 km/h (122 mph or 54 m/s).
This velocity is the asymptotic limiting value of the acceleration process, because the effective forces on the body balance each other more and more closely as the terminal velocity is approached. In this example, a speed of 50 % of terminal velocity is reached after only about 3 seconds, while it takes 8 seconds to reach 90 %, 15 seconds to reach 99 % and so on.
- Higher speeds can be attained if the skydiver pulls in his or her limbs (see also ).
- In this case, the terminal velocity increases to about 320 km/h (200 mph or 90 m/s), which is almost the terminal velocity of the diving down on its prey.
- The same terminal velocity is reached for a typical,30-06 bullet dropping downwards—when it is returning to earth having been fired upwards, or dropped from a tower—according to a 1920 U.S.
Army Ordnance study. Competition speed skydivers fly in the head down position and reach even higher speeds. The current world record is 1 357.6 km/h (843.6 mph, 1.25) by, who jumped from 38 969.4 m (127 852.4 ft) above earth on 14 October 2012.
- For, and for short distances of fall at other than “ground” level, g in the above equations may be replaced by G ( M + m ) r 2 }}} where G is the, M is the mass of the astronomical body, m is the mass of the falling body, and r is the radius from the falling object to the center of the astronomical body.
- Removing the simplifying assumption of uniform gravitational acceleration provides more accurate results. We find from the :
- The time t taken for an object to fall from a height r to a height x, measured from the centers of the two bodies, is given by:
t = π 2 − arcsin ( x r ) + x r ( 1 − x r ) 2 μ r 3 / 2 }-\arcsin }} + }\ (1- })}}} }}\,r^ } where μ = G ( m 1 + m 2 ) +m_ )} is the sum of the of the two bodies. This equation should be used whenever there is a significant difference in the gravitational acceleration during the fall.
How fast do humans fall per second?
Acceleration Today, let’s think about falling. The University of Houston’s College of Engineering presents this series about the machines that make our civilization run, and the people whose ingenuity created them. T he concept of acceleration is hard to see clearly without calculus and graphs.
Yet acceleration is with us every waking moment. We all swim in the same sea of uniform gravitational acceleration. We feel it all the time. Every time we drop or toss an object, gravity acts upon it in the same way. Jump from a height of five feet, and you’ll strike the earth at eighteen feet per second.
From a ten-foot wall, that becomes twenty-five feet per second. So when you double the height, you don’t double the speed you reach. Speed rises only as the square root of the height of the fall. By the way, you start endangering your limbs at about twenty feet per second (depending on your age and physical condition).
Gravity will accelerate any object at a rate of 32 feet per second per second. But what do we do with that number? What it means is that if we fall for one second we’ll reach a speed of 32 feet per second. After two seconds we reach 64 feet per second. The speed rises as the square root of height, but in direct proportion to time.
So acceleration is trickier than it might first seem. Nothing accelerates until a force acts upon it. Yet we feel no force as we fall. The force of gravity is there, acting on every molecule in our bodies – but the force is unopposed, so we feel nothing.
- Not until we stand on a solid floor do we feel the force of gravity.
- The floor is what resists gravity, and it acts only on our feet.
- So an orbiting astronaut, who feels no gravity, is in a perpetual free fall, constantly accelerating toward Earth and hurtling forward at the same time.
- The Space Shuttle keeps falling away from a straight path, but just fast enough to stay a constant height above Earth as it falls – and falls, and falls.
Swing a rock on a string, and it follows the same kind of circular path as the Space Shuttle does. But there’s no significant force of gravity to attract the rock toward you. That’s why you had to replace gravity with a string. Now you feel just how much force it takes to accelerate the rock away from straight flight.
Of course most accelerations don’t have the uniformity of gravity. A rising elevator accelerates at first, and we feel our weight increase by a few pounds. When we decelerate at the 18th floor, our weight drops just a tad. (That can be a nice feeling.) But too many people don’t get it – like motorists who tailgate or don’t slow down for a curve on an icy road.
Acceleration can deceive us. That’s why Isaac Newton, who first explained how force and acceleration are related, was also an inventor of calculus – that special language for explaining how things change in time and space. Acceleration is so much clearer when we have that new language to describe it.
- I’m John Lienhard, at the University of Houston, where we’re interested in the way inventive minds work.
- (Theme music)
- I include no reference material with this episode, since the ideas in it may be found in any beginning physics book at the high-school or college level. Some useful expressions for the motion of a body that starts out stationary and is acted upon by a uniform gravitation, a, for a time, t, are:
- The distance traveled is s = at^2/2
- And the speed it reaches is v = sqrt(2as) = at
For these formulae to work properly, the units must be consistent. Express everything either in feet and seconds or in meters and seconds. The acceleration of gravity is 32.17 ft/s^2 or 9.807 m/s^2. Astronaut Mary Ellen Weber, weightless and falling within a KC-135 aircraft. By flying in a ballistic parabola, the aircraft moves as a projectile would. (Photo courtesy of NASA)
What is the highest terminal velocity on Earth?
Examples – Graph of velocity versus time of a skydiver reaching a terminal velocity. Based on air resistance, for example, the terminal speed of a in a belly-to-earth (i.e., face down) position is about 55 m/s (180 ft/s). This speed is the limiting value of the speed, and the forces acting on the body balance each other more and more closely as the terminal speed is approached.
- In this example, a speed of 50% of terminal speed is reached after only about 3 seconds, while it takes 8 seconds to reach 90%, 15 seconds to reach 99% and so on.
- Higher speeds can be attained if the skydiver pulls in their limbs (see also ).
- In this case, the terminal speed increases to about 90 m/s (300 ft/s), which is almost the terminal speed of the diving down on its prey.
The same terminal speed is reached for a typical bullet dropping downwards—when it is returning to the ground having been fired upwards, or dropped from a tower—according to a 1920 U.S. Army Ordnance study. Competition fly in a head-down position and can reach speeds of 150 m/s (490 ft/s).
- The current record is held by who jumped from an altitude of 38,887 m (127,582 ft) and reached 380 m/s (1,200 ft/s), though he achieved this speed at high altitude where the density of the air is much lower than at the Earth’s surface, producing a correspondingly lower drag force.
- The biologist wrote, To the mouse and any smaller animal presents practically no dangers.
You can drop a mouse down a thousand-yard mine shaft; and, on arriving at the bottom, it gets a slight shock and walks away. A rat is killed, a man is broken, a horse splashes. For the resistance presented to movement by the air is proportional to the surface of the moving object.
How far do you fall in 12 seconds?
Examples – Examples of objects in free fall include:
- A spacecraft (in space) with propulsion off (e.g. in a continuous orbit, or on a suborbital trajectory ( ballistics ) going up for some minutes, and then down).
- An object dropped at the top of a drop tube,
- An object thrown upward or a person jumping off the ground at low speed (i.e. as long as air resistance is negligible in comparison to weight).
Technically, an object is in free fall even when moving upwards or instantaneously at rest at the top of its motion. If gravity is the only influence acting, then the acceleration is always downward and has the same magnitude for all bodies, commonly denoted, Since all objects fall at the same rate in the absence of other forces, objects and people will experience weightlessness in these situations. Examples of objects not in free-fall:
- Flying in an aircraft: there is also an additional force of lift,
- Standing on the ground: the gravitational force is counteracted by the normal force from the ground.
- Descending to the Earth using a parachute, which balances the force of gravity with an aerodynamic drag force (and with some parachutes, an additional lift force).
The example of a falling skydiver who has not yet deployed a parachute is not considered free fall from a physics perspective, since they experience a drag force that equals their weight once they have achieved terminal velocity (see below). Measured fall time of a small steel sphere falling from various heights. The data is in good agreement with the predicted fall time of, where h is the height and g is the free-fall acceleration due to gravity. Near the surface of the Earth, an object in free fall in a vacuum will accelerate at approximately 9.8 m/s 2, independent of its mass, With air resistance acting on an object that has been dropped, the object will eventually reach a terminal velocity, which is around 53 m/s (190 km/h or 118 mph ) for a human skydiver.
- The terminal velocity depends on many factors including mass, drag coefficient, and relative surface area and will only be achieved if the fall is from sufficient altitude.
- A typical skydiver in a spread-eagle position will reach terminal velocity after about 12 seconds, during which time they will have fallen around 450 m (1,500 ft).
Free fall was demonstrated on the moon by astronaut David Scott on August 2, 1971. He simultaneously released a hammer and a feather from the same height above the moon’s surface. The hammer and the feather both fell at the same rate and hit the surface at the same time.
Can a human survive hitting water at terminal velocity?
The upper survival limits of human tolerance to impact velocity in water are evidently close to 100 ft/sec (68.2 mph) corrected velocity, or the equivalent of a 186-foot free-fall.
How fast do you fall in 6 seconds?
|Accel – m/sec 2
|Velocity – m/sec
|Distance – meters
What would fall faster a feather or a brick?
A feather and a brick would fall at the same rate and impact the ground at the same time if dropped together in a vacuum. The feather falls more slowly due to air resistance when it is dropped in normal conditions. Both heavy and light objects will fall at the same speed if they are in a vacuum.
What happens if you go past terminal velocity?
terminal velocity, steady speed achieved by an object freely falling through a gas or liquid. A typical terminal velocity for a parachutist who delays opening the chute is about 150 miles (240 kilometres) per hour. Raindrops fall at a much lower terminal velocity, and a mist of tiny oil droplets settles at an exceedingly small terminal velocity.
- An object dropped from rest will increase its speed until it reaches terminal velocity; an object forced to move faster than its terminal velocity will, upon release, slow down to this constant velocity.
- Terminal velocity is achieved, therefore, when the speed of a moving object is no longer increasing or decreasing; the object’s acceleration (or deceleration) is zero.
The force of air resistance is approximately proportional to the speed of the falling object, so that air resistance increases for an object that is accelerating, having been dropped from rest until terminal velocity is reached. At terminal velocity, air resistance equals in magnitude the weight of the falling object.
Can a car reach terminal velocity?
Terminal Velocity | Revision Science If an object is falling through a fluid, e.g. air or water, as its speed increases the drag on it will also increase. Eventually a speed is reached where the upward force will equal the weight of the object. As there is no net force on the object the acceleration will be zero. : Terminal Velocity | Revision Science
Which will fall first heavy or light?
Heavier objects hit the ground first as they have very less air resistance.
What happens if you drop two objects from the same height?
2 balls similar in size but different mass 2 aluminum tart pans Chair or table (or both) A ruler or metric tape (optional) Beam balance (optional) A chronometer or something to measure the time (optional) A camera to record the experiment (optional)
In the kit there are different sets of balls, repeat the experiment with all the possible wooden and rubber balls combinations. Make sure to label the balls and measure them to make good comparisons. If you are working at home and do not have the exact materials, you can always substitute the balls with clay or playdough (see suggested resources for a recipe of homemade playdough).
- If you do not have either clay or playdough, then find two objects around the house that have the same shape but different weights.
- For example, two identical water bottles, one full and the other one with less water or no water.
- The purpose of this experiment is to test if objects with different masses but the same shape fall at the same time.
Instead of aluminium tart pans you can use aluminum foil or any other type of paper/foil that will produce a sound when the dropped objects hit them. As with activity 1, we ask the students to follow the scientific method to design the experiment.
Can you survive a 10 Metre fall?
How big a fall can a person survive? While even short drops can be lethal, people have survived horrendous falls. In 1972, Vesna Vulovic, a cabin attendant, survived a 10,160m fall when the DC-9 she was in exploded over what is now the Czech Republic.
Earlier this week, a 102-year-old woman survived after toppling from her fourth-floor balcony in Turin. Fortunately, her fall was broken by a children’s playhouse. In very high falls, bodies can reach terminal velocity, the speed at which air resistance becomes so high it cancels out the acceleration due to gravity.
Once at terminal velocity, you can fall as far as you like and you won’t gather any more speed. Vulovic undoubtedly reached terminal velocity before hitting the ground, but it is hard to achieve when falling from a building. “A free-falling 120lb woman would have a terminal velocity of about 38m per second,” says Howie Weiss, a maths professor at Penn State University.
And she would achieve 95% of this speed in about seven seconds.” That equates to a fall of around 167m, which is nearer 55 storeys high. Falls can kill by inflicting damage to any number of vital organs, but the most common reason is due to a key artery’s route through the body. “Most people who fall from a height die because they fracture their spine near the top and so transect the aorta which carries blood out of the heart,” says Sean Hughes, professor of surgery at Imperial College, London.
Landing on your side might be the best way to survive a fall, adds Hughes. It doesn’t take much of a fall to cause damage. “From a height of 3m you could fracture your spine,” he says. “At around 10m, you’re looking at very serious injuries.” Ian Sample : How big a fall can a person survive?
Can you survive a 30 meter fall?
Abstract – The injuries caused by high falls from over the seventh floor are considered mostly fatal. It is possible to survive the high fall from over 30 metres at landing on the surface of high deformity (snow or water). The Injury Severity Score (ISS) due to a high fall is influenced by the height from which the body has fallen, then, the body and surface features, and finally, the manner of body impact on to the surface.
- The aim of the study was determining the possibility of the height estimation that caused the fatality of the impact, considering the severity of injury expressed by ISS.
- A retrospective autopsy study was done on the materials of Institute of Forensic Medicine in Belgrade, during a twenty-year period: 1981-2000.
The autopsy records were analyzed together with clinical medical data, of the deadly injured due to high falls on to a solid surface. ISS value was determined in each case. The height of fall was determined on the basis of police reports, i.e. death scene analysis.
- The results were done statistically (linear correlation).
- The sample included 660 cases: 469 males (71%) and 191 females (29%).
- The average age of the examined sample was 44.66 (SD=6.62).
- The number of 290 cases (44%) were accidental deaths, while 370 were suicidal ones (56%).
- Only few injured due to high falls up to 7 metres had ISS value below 26.
Deaths in these cases were caused by complications of the injuries. The ISS value in the injured rose with the height from which the victim had fallen: ISS was 25 in all falls over 7 metres of height. In all cases were severe, critical injuries of one organic system (mostly severe head injuries).
- According to the analysis of our sample, we concluded that it was not possible to determine the precise height of fatal falls only on the basis of the injury severity score estimation by ISS.
- This determination, approximate one, was possible only in falls on to a solid surface up to 30 metres.
- The same determination was not possible by the analysis of the time of survival.
It is obvious that determining the height of fall is more possible by types and combinations of single injuries which are, single or combined with other injuries, characteristic for single mechanisms of primary body contact with the solid surface depending on the height of fall.
What is the highest fall a human has survived?
How Vesna Vulović survived the highest fall ever with no parachute Share On the 26th of January 1972, Vesna Vulović was a flight attendant onboard JAT Yugoslav Airlines Flight 367. The flight path, between Stockholm in Sweden and Belgrade in Serbia, took the aircraft over Czechoslovakia – now the Czech Republic – and that is where the plane exploded into three pieces.
The explosion and crash killed everyone on board. Everyone except Vesna, who survived a fall of 33,333 feet (10,160 metres; 6.31 miles).50 years on, this remains the highest fall survived without a parachute ever. YT JAT Flight 367 had two scheduled stopovers in between Stockholm and Belgrade. First was Copenhagen in Denmark, which is where the secondary cabin crew – including Vesna – boarded the plane.
They never reached the second stopover in Zagreb, Croatia. As fate would have it, Vesna was not actually scheduled to be working on Flight 367, as she revealed in a with Green Light. However, the airline had confused her for another stewardess with the same first name, thus the plane departed Denmark with 23-year-old Vesna Vulović on board. At 4:01 p.m., 46 minutes after take off, an explosion in the luggage compartment tore the McDonnell Douglas DC-9 aircraft into three pieces. As the cabin depressurized, the passengers and other flight crew were believed to have been sucked out of the plane into freezing temperatures, falling to their deaths. The fuselage separated from the rest of the plane and hurtled towards the ground in a heavily wooded area near the Czechoslovak village of Srbská Kamenice. It crash landed in the thick snow at a favourable angle, which is most likely what saved Vesna’s life.
- Additionally, Vesna’s physicians determined that her low blood pressure caused her to quickly pass out when the cabin depressurized, which prevented her heart from bursting upon impact.
- Vesna was found screaming inside the wreckage by Bruno Honke, a local villager and former World War 2 medic who was able to administer vital first aid before rescuers arrived.
Although Vesna survived, she sustained extremely serious injuries and spent the following days in a coma. She suffered a fractured skull, two broken legs, three broken vertebrae, a fractured pelvis, several broken ribs and temporary paralysis below the waist.
- Amazingly, Vesna was able to walk again after ten months, albeit with a permanent limp due to the twisting of her spine.
- She had no memory of the crash or of anything from the following month.
- YT In her home country of Yugoslavia, Vesna Vulović became a national icon, honoured by the President of Yugoslavia, Josip Broz Tito.
A song was even written about her, titled “Vesna stjuardesa” (“Vesna the Stewardess”), by Serbian-folk-singer Miroslav Ilić. As part of the Guinness World Records Hall of Fame ceremony in 1985, Paul McCartney presented Vesna with a certificate and medal for achieving the highest fall survived without a parachute,
How do you explain terminal velocity to a child?
Terminal velocity is the speed when an object falling through a fluid (usually air ) is no longer getting faster. Terminal velocity happens at the moment in time that the force of gravity, called weight, is the same as the opposite force of air resistance or friction,
In other words, terminal velocity is the point at which the velocity (speed of moving of the falling object) is no longer getting greater. The gravitational force minus the force of drag (or air resistance) equals zero. An object continues to fall steadily until air resistance becomes so great that it equals the pull of gravity and the object can fall no faster.
Besides weight, terminal velocity depends on other factors such as shape and cross sectional area.
Why is it called terminal velocity?
Terminal Velocity On October 14, 2012, Felix Baumgartner, a skydiver from Austria, did something incredible. He jumped from a height of 39,068 metres above Earth’s surface, hoping to become the first skydiver to go faster than the speed of sound. Why did he jump from so high? It’s because the law of gravity we learn about in school doesn’t work the same way in our atmosphere.
What is a synonym for terminal velocity?
TERMINAL VELOCITY Synonyms: 4 Synonyms & Antonyms for TERMINAL VELOCITY | Thesaurus.com
Compare Synonyms On this page you’ll find 5 synonyms, antonyms, and words related to terminal velocity, such as: escape velocity, flash, greased lightning, and lightning speed.
Ball and closely-prisoned man plummeted downward; slowing abruptly, with a horrible deceleration, to terminal velocity, | Edward Elmer Smith But the terminal velocity of an airplane is a lot more than that. | David Goodger ([email protected]) These were to demonstrate that the ship would dive to terminal velocity, | David Goodger ([email protected])
I went out to do the terminal-velocity dive with the nine-g pull-out. | David Goodger ([email protected]) Then I would do the grand dive of ten thousand feet to terminal velocity and pull out to nine g. | David Goodger ([email protected])
Synonym of the Day Sep 13, 2023 Choose the synonym for Browse Follow us Get the Word of the Day every day! © 2023 Dictionary.com, LLC : TERMINAL VELOCITY Synonyms: 4 Synonyms & Antonyms for TERMINAL VELOCITY | Thesaurus.com